1. Field of the Invention:
The present invention relates to a cord cutter head for use in, for example, a grass trimmer.
2. Description of the Prior Art:
In general, a cutter head has a flexible cord made of a plastic such as nylon and adapted to serve as a cutter blade. The cord cutter head also has a housing fixed to one end of a drive shaft, and a spool accommodated by the housing and carrying the cutter cord wound thereon. In operation, the free end of the cutter cord is extracted by a desired length out of the housing. The drive shaft is drivingly connected to a suitable power source such as a small-sized internal combustion engine, through a suitable transmission.
When the cutter cord outside the housing has been worn out or cut accidentally, it is necessary to extract a new portion of the cutter cord from the housing. Hitherto, the additional extraction of the new portion of the cutter head was conducted semi-automatically by means of, for example, a device generally referred to as an "inertia shifter".
Such a conventional cord cutter head, however, suffers from a disadvantage in that troubles such as cutting or welding of the cord, as well as rewinding or retraction of the cutter cord into the housing, tend to occur during operation and also in that the construction is complicated and the size is increased with a result that the weight and the cost are increased undesirably. In addition, handling and operations, as well as repair and maintenance, are generally difficult to conduct.